Draft objective for per- and polyfluoroalkyl substances in Canadian drinking water: Overview

On this page

• Purpose of consultation
• Information on objectives for drinking water
• Proposed objective value
• Background

Purpose of consultation

This technical document has been developed with the intent to provide regulatory authorities and decision-makers with an objective for per- and polyfluoroalkyl substances in Canadian drinking water supplies.

This document is available for a 60-day public consultation period. The purpose of this consultation is to solicit comments on the proposed objective, on the approach used to develop it and on the potential impacts of implementing it.

Please send comments (with rationale, where required) to Health Canada via email to water-eau@hc-sc.gc.ca. If email is not feasible, comments may be sent by postal mail to this address:

Water and Air Quality Bureau, Health Canada
269 Laurier Avenue West, A.L. 4903D
Ottawa, ON K1A 0K9

All comments must be received before April 12, 2023. Comments received as part of this consultation will be shared with members of the Federal-Provincial-Territorial Committee on Drinking Water (CDW), along with the name and affiliation of their author. Authors who do not want their name and affiliation shared with CDW members should provide a statement to this effect along with their comments.

Note that this objective document will be revised following the evaluation of comments received. This document should be considered as a draft for comment only.

Information on objectives for drinking water

The main responsibility of the CDW is to work in collaboration with Health Canada to develop and update the Guidelines for Canadian Drinking Water Quality.

The development of a guideline follows a multi-year, comprehensive scientific process and takes many years to finalize. In rare instances, new information on a contaminant raises concerns that need to be addressed more quickly than the guideline development process allows. In such cases, Health Canada, in collaboration with the provincial and territorial governments, may establish a drinking water objective to reduce exposure while a guideline is revised or developed. This is the case with per- and polyfluoroalkyl substances (PFAS).

Drinking water objectives set out a goal for a maximum level of a contaminant in drinking water, taking into account available treatment technology and analytical methods. They are based on a review of scientific research and consider international regulatory information available at the time of their development. Drinking water objectives are externally peer reviewed to ensure scientific integrity.

Proposed objective value

To reduce exposure from drinking water, an objective of 30 ng/L is proposed for the sum of total per- and polyfluoroalkyl substances (PFAS) detected in drinking water. Total PFAS should be calculated using the full list of substances in either United States Environmental Protection Agency (U.S. EPA) Method 533 or U.S. EPA Method 537.1, or both (see Appendix A). A jurisdiction could also validate and apply an alternate analytical method that quantifies a minimum of 18 PFAS. For the purposes of this proposed objective, a result of non-detect is considered to have a value of zero. It is recommended that treatment plants strive to maintain PFAS concentrations in drinking water as low as reasonably achievable (ALARA).

Background

In 2018 and 2019, Health Canada established drinking water guidelines for perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), and screening values for 9 other PFAS including:

• perfluorobutanoate (PFBA)
• perfluoropentanoate (PFPeA)
• perfluorohexanoate (PFHxA)
• perfluoroheptanoate (PFHpA)
• perfluorononanoate (PFNA)
• perfluorobutane sulfonate (PFBS)
• perfluorohexanesulfonate (PFHxS)
• 6:2 fluorotelomer sulfonate (6:2 FTS)
• 8:2 fluorotelomer sulfonate (8:2 FTS)

These values applied to water intended for human consumption. Note that full names for any other PFAS mentioned in this document are in Appendix A or B.

On April 24, 2021, the Government of Canada notified people living in Canada of its intent to move forward with activities that address PFAS as a class. In accordance with this strategy and considering new scientific evidence in the field of hazard and exposure assessment as well as in treatment and analytical technologies, a review of the current PFAS drinking water guidelines and screening values is under way.

To reduce potential exposure to PFAS through drinking water while the reassessment of the guidelines and screening values is being completed, an objective based on the sum of specific detected PFAS is proposed for Canadian drinking water. This objective, when finalized, will replace the 2 previous drinking water guidelines and 9 screening values derived for individual PFAS. This technical document was prepared in collaboration with the Federal-Provincial-Territorial Committee on Drinking Water (CDW).